#include <stdio.h>
#include <stdlib.h>
#define N 1000000

int main()
{
  double x,y,x1,y1,r;
  int i;
  x=0;
  y=0;
  i=N;
  while(i)
  {
    r=(double)rand()/RAND_MAX;
    printf("%lf %lf\n", x,y);
    if(r<0.65)
    {
      x1=0.5*x+0.5;
      y1=0.5*y;
    }
    else if(r<0.8)
    {
      x1=0.5*x+0.5;
      y1=0.5*y+0.5;
    }
    else if(r<0.9)
    {
      x1=0.5*x;
      y1=0.5*y+0.5;
    }
    else
    {
      x1=0.3*x+0.3;
      y1=0.3*y+0.3;
    }
    x=x1;
    y=y1;
    i--;
  }
  return 0;
}